Provide some usage analytics

Problem / Motivation

Let's provide some usage analytics! We should be able to get some from Tugboat and maybe storing some of our own info.

• Repo statistics: https://api.tugboatqa.com/v3#tag/Repositories/paths/~1repos~1%7Bid%7D~1s...
• Repo previews (show # of active previews): https://api.tugboatqa.com/v3#tag/Repositories/paths/~1repos~1%7Bid%7D~1p...